Dye-sensitized photoelectric conversion device

ABSTRACT

The present invention relates to an organic dye-sensitized semiconductor device and to a solar cell using it and, particularly, to a photoelectric conversion device using semiconductor fine particles sensitized with a dye having an acrylic acid part and a solar cell using it. According to the present invention, a low-cost photoelectric conversion device having favorable conversion efficiency and a solar cell can be obtained.

TECHNICAL FIELD

The present invention relates to photoelectric conversion devices usingsemiconductor fine particles sensitized with organic dye(s) and solarcells using semiconductor fine particles sensitized with organic dye(s),and in particular to a photoelectric conversion device characterized byusing oxide semiconductor fine particles sensitized with a dye having anacrylic acid part(s) and a solar cell utilizing the same.

BACKGROUND OF THE INVENTION

A solar cell utilizing sunlight as an alternative energy source to afossil fuel such as petroleum, coal or the like has been in the spotlight. Today, developments and studies are being conducted onenhancement of efficiency and the like of a silicon solar cell whichuses crystalline or amorphous silicon, a compound semiconductor solarcell which uses gallium, arsenic or the like. However, since much energyis required for producing these solar cells and the cost of them ishigh, there is a problem that it is difficult to put them to generaluse. Further, a photoelectric conversion device which uses semiconductorfine particles sensitized with dye(s) and a solar cell which uses thisdevice have been known whereupon materials for use in producing them andtechniques for producing them have been disclosed. (B. O'Regan and M.Gratzel Nature, 353, 737 (1991), M. K. Nazeeruddin, A. Kay, I. Rodicio,R. Humphry-Baker, E. Muller, P. Liska, N. Vlachopoulos, M. Gratzel, J.Am. Chem. Soc., 115, 6382 (1993) e.t.c.). This photoelectric conversiondevice is produced by using a comparatively low-cost oxide semiconductorsuch as titanium oxide or the like. Since there is a possibility that aphotoelectric conversion device can be obtained in low cost comparedwith a solar cell which uses a conventional silicon or the like, thisdevice has been remarked. However, in order to obtain a device havinghigh conversion efficiency, a ruthenium-type complex is used as asensitizing-dye wherein the dye itself is high in cost and there also isa problem in supply thereof. Further, although it has already beenattempted to use an organic dye as a sensitizing-dye, it is a presentsituation that, due to low conversion efficiency and the like, it hasnot yet been used practically.

A development of a photoelectric conversion device, using an organicdye-sensitized semiconductor, which has high conversion efficiency aswell as high practicability has been required.

DISCLOSURE OF THE INVENTION

The present inventors have made an extensive effort to solve theabove-described problems and, as a result, have found that aphotoelectric conversion device having high conversion efficiency can beobtained by sensitizing semiconductor fine particles with a dye havingan acrylic acid part, namely, ethylenic double bond residue having acarboxyl group and, then, producing a photoelectric conversion device toachieve the present invention.

Namely, the present invention relates to

(1) a photoelectric conversion device, characterized by comprising oxidesemiconductor fine particles sensitized with a dye having an acrylicacid part,

(2) a photoelectric conversion device, characterized by comprising oxidesemiconductor fine particles sensitized with a dye represented by thefollowing formula (1) having an acrylic acid part:

wherein A1 and A2 each independently represent a carboxyl group, a cyanogroup, an alkoxycarbonyl group, an acyl group, a nitro group, a cyclichydrocarbon residue which may be substituted, a heterocyclic residuewhich may be substituted, an amino group which may be substituted, ahydroxyl group, a hydrogen atom, a halogen atom or an alkyl group whichmay be substituted; X represents an aromatic hydrocarbon residue whichmay be substituted, a heterocyclic residue which may be substituted, anorganic metal complex residue which may be substituted or an amino groupwhich may be substituted; n represents an integer from 1 to 6; and, whenn is 2 or more, that is, a plurality of A1 and a plurality of A2 arepresent, each A1 and each A2 independently represent any one of theabove-described groups or residues which may be same with or differentfrom each other, and further, except for the A1bound to the carbon atomto which the carboxyl group in an acrylic part is bound, two A1s or eachA1 in a plurality of A1, A2 or each A2 in a plurality of A2 and X may bebound together to form a ring which may be substituted,

(3) the photoelectric conversion device as mentioned in theabove-described (2), wherein n is from 1 to 3 in the formula (1),

(4) the photoelectric conversion device as mentioned in theabove-described (2), characterized by that at least one of A1 and A2 or,when plural A1s and plural A2s are present, at least one thereof is acyano group or a carboxyl group in the formula (1),

(5) the photoelectric conversion device as mentioned in theabove-described (4), characterized by that A1 in the formula (1) is acyano group or a carboxyl group wherein the A1 binds to the same carbonatom as that the carboxyl group in an acrylic part is bound to.

(6) the photoelectric conversion device as mentioned in any one of theabove-described (2) to (5), wherein X in the formula (1) is an aromatichydrocarbon residue having a substituted amino group,

(7) the photoelectric conversion device as mentioned in any one of theabove-described (2) to (5), wherein the heterocyclic residue is aheterocyclic residue which is a 5- or 6-membered ring containing from 1to 3 hetero atoms and may be substituted, or a heterocyclic residuecomprising a condensed ring, having from 8 to 15 carbon atoms, whichcontains a 5- or 6-membered heterocycle containing from 1 to 3 heteroatoms,

(8) the photoelectric conversion device as mentioned in theabove-described (6), wherein X of the formula (1) is an aromatichydrocarbon residue comprising an aromatic ring having from 6 to 16carbon atoms,

(9) the photoelectric conversion device as mentioned in theabove-described (8), wherein the aromatic hydrocarbon residue in X ofthe formula (1) is a phenyl group having a mono- or di- (C1 to C4)alkyl-substituted amino group, wherein the above-described phenyl groupmay further be substituted by one or two substituents selected from thegroup consisting of a halogen atom, an alkyl group having from 1 to 4carbon atoms and an alkoxy group having from 1 to 4 carbon atoms,

(10) the photoelectric conversion device as mentioned in any one of theabove-described (1) to (9), characterized by comprising oxidesemiconductor fine particles sensitized with simultaneously two or moresensitizing-dyes comprising at least one dye having an acrylic acidpart,

(11) the photoelectric conversion device as mentioned in theabove-described (10), characterized by comprising oxide semiconductorfine particles sensitized with simultaneously three or more types ofsensitizing-dyes,

(12) the photoelectric conversion device as mentioned in any one of theabove-described (1) to (11), wherein the oxide semiconductor fineparticles comprise titanium dioxide as an essential component,

(13) the photoelectric conversion device as mentioned in any one of theabove-described (1) to (12), wherein a dye is adsorbed to the oxidesemiconductor fine particles in the presence of an inclusion compound,and

(14) a solar cell, characterized by comprising the photoelectricconversion device as mentioned in any one of the above-described (1) to(13).

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in detail below. A photoelectricconversion device according to the present invention uses an oxidesemiconductor sensitized with a dye having an acrylic acid part. The dyehaving an acrylic acid part to be used in the present invention is notparticularly limited, so long as the dye has an acrylic acid part, but,as being a favorable dye, is mentioned a dye represented by thefollowing general formula (1):

wherein A1, A2, X and n each have the same meaning as described above.

Unless stated otherwise, the term “dye” herein represented by thegeneral formula (1) is intended to mean any one of a free acid and asalt thereof represented by the general formula (1).

Examples of salts of compounds represented by the general formula (1)include a metallic salt of a carboxylic acid portion of theabove-described formula, for example, a salt with an alkali metal,alkali earth metal or the like such as lithium, sodium, potassium,magnesium, calcium or the like, and a salt such as a quaternary ammoniumsalt such as an organic base, for example, tetramethyl ammonium,tetrabutyl ammonium, pyridinium, imidazolium or the like.

Further, A1 and A2 each independently represent a carboxyl group, acyano group, an alkoxycarbonyl group, an acyl group, a nitro group, acyclic hydrocarbon residue which may be substituted, a heterocyclicresidue which may be substituted, an amino group which may besubstituted, a hydroxyl group, a hydrogen atom, a halogen atom or analkyl group which may be substituted. Furthermore, when a plurality ofA1 and a plurality of A2 are present, each A1 and each A2 independentlyrepresent the above-described groups which may be identical with ordifferent from each other.

As substituents in the cyclic hydrocarbon residue which may besubstituted and the heterocyclic residue which may be substituted,mentioned are, but not particularly limited to, an alkyl group, an arylgroup, a cyano group, an isocyano group, a thiocyanato group, anisothiocyanato group, a nitro group, a nitrosyl group, an acyl group, ahalogen atom, a hydroxyl group, a phosphoric acid group, a phosphoricacid ester group, a mercapto group which may be or may not besubstituted, an amino group which may be or may not be substituted, anamide group which may be or may not be substituted, an alkoxyl group, analkoxyalkyl group, a carboxyl group, an alkoxycarbonyl group, a sulfogroup and the like.

As alkyl groups, mentioned are saturated and unsaturated groups ofstraight-chain, branched-chain and cyclic types which may besubstituted, wherein, they have preferably from 1 to 36 carbon atoms,and more preferably it is the straight-chain saturated alkyl grouphaving from 1 to 20 carbon atoms which may be substituted. As the cyclicgroup, mentioned are, for example, a cycloalkyl having from 3 to 8carbon atoms and the like. These alkyl groups may further be substitutedby the above-described substituents (except alkyl groups).

As aryl groups, mentioned are groups, in which a hydrogen atom isremoved from an aromatic ring, mentioned in the part of cyclichydrocarbon residues mentioed below and the like. The aryl groups mayfurther be substituted by the above-described groups or the like.

Examples of acyl groups include an alkyl carbonyl group having from 1 to10 carbon atoms, an aryl carbonyl group and the like, and preferably thealkyl carbonyl group having from 1 to 4 carbon atoms. As a specificexample, mentioned are an acetyl group, a propionyl group and the like.

As halogen atoms, mentioned are chlorine, bromine, iodine atoms and thelike.

As phosphoric acid ester groups, mentioned are a phosphoric acid (C1 toC4) alkyl ester and the like.

As mercapto groups which are substituted or un substituted, mentionedare a mercapto group, an alkyl mercapto group and the like.

As amino groups which are substituted or unsubstituted, mentioned are anamino group, a mono- or dialkyl amino group, a mono- or diaromatic aminogroup and the like, and, as those, mentioned are a mono- or dimethylamino group, a mono- or diethyl amino group, a mono- or dipropyl aminogroup, a monophenyl amino group, a benzyl amino group and the like.

As amide groups which are substituted or unsubstituted, mentioned are anamide group, an alkyl amide group, an aromatic amide group and the like.

Examples of alkoxyl groups include an alkoxyl group having from 1 to 10carbon atoms and the like.

Examples of alkoxyalkyl groups include a (C1 to C10) alkoxy (C1 to C4)alkyl group and the like.

Examples of alkoxycarbonyl groups include an alkoxycarbonyl group havingfrom 1 to 10 carbon atoms and the like.

Further, acidic groups such as a carboxyl group, a sulfo group, aphosphoric acid group and the like may be in a state in which they formsalts, for example, salts of metals such as lithium, sodium, potassium,magnesium, calcium and the like, and quaternary ammonium salts such astetramethyl ammonium, tetrabutyl ammonium, pyridinium, imidazolium andthe like.

The cyclic hydrocarbon residue means a group obtained by removing ahydrogen atom from a cyclic hydrocarbon.

Examples of cyclic hydrocarbons include benzene, naphthalene,anthracene, phenanthrene, pyrene, indene, azulene, fluorene,cyclohexane, cyclopentane, cyclohexene, cyclopentene, cyclohexadiene,cyclopentadiene and the like and as cyclic hydrocarbon residues,mentioned are groups obtained by removing a hydrogen atom from each ofthese cyclic hydrocarbons.

The heterocyclic residue means a group obtained by removing a hydrogenatom from a heterocyclic compound and, as heterocyclic residues,illustrated are those mentioned in the part of heterocyclic residuesrepresented by X mentioned below and the like. Examples of preferableheterocyclic residues in A1 or A2 include residues obtained by removinga hydrogen atom from each of cyclic compounds such as pyridine,pyrazine, piperizine, morpholine, indoline, thiophene, furan, oxazole,thiazole, indole, benzothiazole, benzoxazole, pyrazine, quinoline andthe like, and these residues may be substituted as described above.

Further, A1 and A2 may be bound with each other to form a ring.Particularly, when n mentioned below is 2 or more and A1 and A2 are eachpresent in a plurality number, any two thereof may be bound with eachother to form a ring. When a ring is formed, any one of A1 and any oneof A2 may be bound with each other without any specific limitation;however, ordinarily, adjacent A1 and A2, adjacent two A1 or adjacent twoA2 form the ring therebetween. The above-described ring may besubstituted. As substituents in a case in which such substituents may behad, mentioned are substituents described in the part of theabove-described cyclic hydrocarbon residues which may be substituted. Asa ring which is formed by allowing A1 and A2, or anyone of A1s which arepresent in a plural number and any one of A2s which are present in aplural number to be bound with each other, mentioned are an unsaturatedhydrocarbon ring or a heterocycle. As such unsaturated hydrocarbonrings, mentioned are a benzene ring, a naphthalene ring, an anthracenering, a phenanthrene ring, a pyrene ring, an indene ring, an azulenering, a fluorene ring, a cyclobutene ring, a cyclopentene ring, acyclohexene ring, a cyclohexadiene ring, a cyclopentadiene ring and thelike; as such heterocycles, mentioned are a pyridine ring, a pyrazinering, an indoline ring, a thiophene ring, a furan ring, a pyran ring, anoxazole ring, a thiazole ring, an indole ring, a benzothiazole ring, abenzoxazole ring, a pyrazine ring, a quinoline ring, a carbazole ring, abenzopyran ring and the like. Among these rings, the cyclobutene ring,the cyclopentene ring, the cyclohexene ring, the pyran ring and the likeare preferable. Further, when A1 or A2 has a carbonyl group, athiocarbonyl group or the like, a cycloketone, a cyclothioketone or thelike may be formed. Examples of compounds which form these rings includecompounds exemplified in the compound from No. 110 to compound No. 118,No. 127 and the like mentioned below.

Preferably A1 and A2 are each independently a carboxyl group, a cyanogroup, an alkoxycarbonyl group, an acyl group, a hydroxyl group, ahydrogen atom, a halogen atom or an alkyl group. Among these groups, thecarboxyl group, the cyano group, the hydrogen atom, the halogen atom,the alkyl group are more preferable. Among such halogen atoms, achlorine atom, a bromine atom and an iodine atom are preferable.Further, when, in the formula (1), A1 is bound to a same carbon atom asthat the carboxyl group is bound to, the carboxyl group or the cyanogroup is particularly preferable.

n is an integer of from 1 to 6.

When n is 1, the general formula (1) is represented by the followingformula (2):

wherein B1 and B2 each independently represent a carboxyl group, a cyanogroup, an alkoxycarbonyl group, an acyl group, a nitro group, a cyclichydrocarbon residue which may be substituted, a heterocyclic residuewhich may be substituted, an amino group which may be substituted, ahydroxyl group, a hydrogen atom, a halogen atom or an alkyl group whichmay be substituted, and further a ring which may be substituted may beformed by using a number of parts of B1, B2 or X; and X represents anaromatic hydrocarbon residue which may be substituted, a heterocyclicresidue which may be substituted, an organic metal complex residue whichmay be substituted or an amino group which may be substituted.Substituent(s) in B1 and B2 may be the same as those mentioned in theabove-described A1 and A2. As preferable combinations among these B1 andB2, mentioned are combinations that B1 is a carboxyl group, a cyanogroup or a hydroxyl group and B2 is a carboxyl group, a cyano group, ahalogen atom, an alkyl group or a hydrogen atom. As more preferablecombinations, mentioned are combinations that B1 is a carboxyl group ora cyano group and B2 is a hydrogen atom.

When n is 2, the general formula (1) is represented by the followingformula (3):

wherein C1, C2, C3 and C4 each independently represent a carboxyl group,a cyano group, an alkoxycarbonyl group, an acyl group, a nitro group, acyclic hydrocarbon residue which may be substituted, a heterocyclicresidue which may be substituted, an amino group which may besubstituted, a hydroxyl group, a hydrogen atom, a halogen atom or analkyl group which may be substituted, and a ring which may besubstituted may be formed by using a number of parts of C1, C2, C3, C4or X; and X represents an aromatic hydrocarbon residue which may besubstituted, a heterocyclic residue which may be substituted, an organicmetal complex residue which may be substituted or an amino group whichmay be substituted. C1, C2, C3 and C4 represent the same groups as thosementioned in the above-described A1 and A2 whereupon substituents andthe like are also the same as those mentioned in the above-described A1and A2. As preferable combinations among these groups, mentioned arecombinations that C1 is a carboxyl group, a cyano group, analkoxycarbonyl group, an acyl group or a hydroxyl group, and C2, C3 andC4 each independently are a carboxyl group, a cyano group, a halogenatom, an alkyl group or a hydrogen atom. As more preferablecombinations, mentioned are combinations that C1 is a carboxyl group ora cyano group, and C2, C3 and C4 are hydrogen atoms.

When n is 3, the general formula (1) is represented by the followingformula (4):

wherein D1, D2, D3, D4, D5 and D6 each independently represent acarboxyl group, a cyano group, an alkoxycarbonyl group, an acyl group, anitro group, a cyclic hydrocarbon residue which may be substituted, aheterocyclic residue which,may be substituted, an amino group whichmaybe substituted, a hydroxyl group, a hydrogen atom, a halogen atom oran alkyl group which may be substituted, wherein a ring which may besubstituted may be formed by using a number of parts of D1, D2, D3, D4,D5, D6 or X; and X represents an aromatic hydrocarbon residue which maybe substituted, a heterocyclic residue which may be substituted, anorganic metal complex residue which may be substituted or an amino groupwhich may be substituted. D1, D2, D3, D4, D5 and D6 represent samegroups as those mentioned in the above-described A1 and A2 whereuponsubstituents and the like are also same as those mentioned in theabove-described A1 and A2. As preferable combinations among thesegroups, mentioned are combinations that D1 is a carboxyl group, a cyanogroup, an alkoxycarbonyl group, an acyl group or a hydroxyl group, andD2, D3, D4, D5 and D6 each independently are a carboxyl group, a cyanogroup, a halogen atom, an alkyl group or a hydrogen atom. As morepreferable combinations, mentioned are combinations that D1 is acarboxyl group or a cyano group, and D2, D3, D4, D5 and D6 are hydrogenatoms.

X represents an aromatic hydrocarbon residue which may be substituted, aheterocyclic residue which may be substituted, an organic metal complexresidue which may be substituted or an amino group which may besubstituted.

The aromatic hydrocarbon residue means a group obtained by removing ahydrogen atom from an aromatic hydrocarbon. As the group obtained byremoving a hydrogen atom from an aromatic hydrocarbon, mentioned are forexample benzene, naphthalene, anthracene, phenanthrene, pyrene, indene,azulene, fluorene and the like and these groups each may be substitutedas described above. Each of these aromatic hydrocarbon residuesordinarily has an aromatic ring (aromatic ring and condensation ringcontaining an aromatic ring or the like) having from 6 to 16 carbonatoms.

As the heterocyclic residue which may be substituted, mentioned is agroup obtained by removing a hydrogen atom from a heterocyclic compoundwhich may be substituted. Examples of such heterocyclic compoundsinclude pyridine, pyrazine, pyrimidine, pyrazole, pyrazolidine,thiazolidine, oxazolidine, pyran, chromene, pyrrole, benzimidazole,imidazoline, imidazolidine, imidazole, pyrazole, triazole, triazine,diazole, morpholine, indoline, thiophene, furan, oxazole, thiazine,thiazole, indole, benzothiazole, naphthothiazole, benzoxazole,naphthoxazole, indolenine, benzoindolenine, pyrazine, quinoline,quinazoline, carbazole and the like, and these compounds may have beensubjected to ring-increasing or hydrogenation and said compounds may besubstituted.

Further, when X is a heterocycle or the like, the heterocycle may bechanged into a quaternary heterocycle and, the quaternary heterocyclemay have a counter ion. There is no specific limitation on such counterions, but ordinary anions are permissible. Specific examples thereofinclude F⁻, Cl⁻, Br⁻, I⁻, ClO4⁻, BF4⁻, PF6⁻, OH⁻, SO4²⁻, CH3SO4⁻,toluene sulfonic acid and the like and, among these, Br⁻, I⁻, ClO4⁻,BF4⁻, PF6⁻, CH3SO4⁻ and toluene sulfonic acid are preferable. Further,instead of the counter ion, the heterocycle may be neutralized by anintramolecular or intermolecular acidic group such as a carboxyl groupor the like.

As the amino group which may be substituted, mentioned are aunsubstituted amino group, a diphenylamino group, a monophenylaminogroup, a dialkylamino group, a monoalkylamino group, an alkylphenylaminogoup, an alkoxyamino group, an acylamino group (for example, abenzoylamino group, an acetylamino group and the like) and the like.

As the organic metal complex residue, mentioned is a group obtained byremoving a hydrogen atom from an organic complex compound. Examples ofsuch organic complex compounds include ferrocene, ruthenocene,titanocene, zirconocene, phthalocyanine, a ruthenium bipyridyl complexand the like.

Further, X may be bound to A1 or A2 to form a ring which may besubstituted. Examples of such rings include a benzene ring, anaphthalene ring, an indene ring, a pyridine ring, a pyrazine ring, apyrimidine ring, a quinoline ring, a thiophene ring, an indolenine ring,a benzoindolenine ring, a pyrazole ring, a pyrazolidine ring, a thiazolering, a thiazolidine ring, a benzothiazole ring, an oxazole ring, anoxazolidine, a benzoxazole ring, a pyran ring, a chromene ring, apyrrole ring, an imidazole ring, a benzimidazole ring, an imidazolinering, an imidazolidine, an indole ring, a furan ring, a carbazole ring,a pyran ring, a benzopyran ring, a phthalocyanine ring, a porphyrinring, ferrocene and the like, and these rings each have may behydrogenated. Specific examples thereof, as shown in compound exampleNos. 90 to 92, from 112 to 115, 118 and the like, include an example inwhich, when X is an N-methyl-N-phenylamino group, X forms abenzothiazole ring, a benzoxazole ring or a benzopyrroline ring bybinding to A2 which is a mercapto group, a hydroxy group or an isopropylgroup, respectively, an example in which, when X is anN-ethyl-N-phenylamino group, X forms a quinoline ring by using A2 andmethylene, and the like.

Further, as a substituent in a case in which the aromatic hydrocarbonresidue, the heterocycle residue or the organic metal complex residue inX is substituted, or as a substituent in a case in which a ring formedby any two of the above-described X, A1 or A2 is substituted, mentionedare same substituents as those on the cyclic hydrocarbons described inthe paragraph of the above-described A1 or A2, a carbonyl group, athiocarbonyl group and the like.

Furthermore, when X, A1 or A2 which forms a ring has a carbonyl group ora thiocarbonyl group, a ring formed by any two of X, A1 and A2 may be aring substituted by O═ or S═ as a substituent, that is, a cyclic ketoneor a cyclic thioketone.

As a preferable substituent in the above-described aromatic hydrocarbonresidue, heterocyclic residue or organic metal complex residue or thelike in X, or a preferable substituent on a ring formed by using any twoof X, A1 and A2, mentioned are an amino group which may be substituted,an alkyl group which may be substituted, an alkoxyl group which may besubstituted, an acetyl group which may be substituted, a hydroxyl group,a halogen atom, O═, S═ and the like. As a further preferablesubstituent, mentioned are an amino group which may be substituted, analkyl group which may be substituted, an alkoxyl group which may besubstituted, O═ and S═. On this occasion, as the amino group which maybe substituted, mentioned are a mono- or dialkyl-substituted aminogroup, a monoalkyl monoaryl-substituted amino group, adiaryl-substituted amino goup, a mono- or dialkylene-substituted aminogroup and the like and, the dialkyl-substituted amino group, thediaryl-substituted amino group are preferable. As the alkyl group whichmay be substituted, mentioned are an aryl-substituted alkyl group, ahalogen atom-substituted alkyl group, an alkoxyl-substituted alkyl groupand the like. As the alkoxyl group which may be substituted, mentionedare an alkoxy-substituted alkoxyl group, a halogen-substituted alkoxylgroup, an aryl-substututed alkoxyl group and the like.

A compound represented by the above-described formula (1) is able tohave structural isomers of a cis form, a trans form and the like.However, the compound can favorably be used as a photosensitizing-dyewithout any particular limitation of these structural isomers.

Among compounds represented by the formula (1), a compound (2) in a caseof n=1 can be obtained by condensing, for example, an acetic acidderivative represented by the formula (5) and a carbonyl derivativerepresented by the formula (6) optionally in the presence of a basiccatalyst such as piperidine, piperazine or the like in an organicsolvent, preferably a polar solvent such as alcohol, for example,methanol, ethanol, propanol or the like at a reflux temperature.

Further, a compound (3) in a case of n=2 can similarly be obtained bycondensing the acetic acid derivative represented by the formula (5) anda carbonyl derivative represented by the formula (7-1) optionally in thepresence of the basic catalyst in a solvent such as the above-describedalcohol or the like.

Furthermore, a derivative in a case of n=3 or more can be produced in asame manner by using a carbonyl derivative represented by the formula(7-2) in place of the carbonyl derivative represented by the formula(7-1). Still further, a derivative in which a ring is formed can beobtained by condensing an acetic acid derivative and a carbonylderivative having a ring or a carbonyl derivative having a ring. Forexample, the derivative can be obtained by using a compound in which aring is formed by A2 and X in the formula (7-1) or a compound in which aring is formed by either A1 nearer to X and A2 nearer to X, or X and A1or A2 in the formula (7-2).

Still furthermore, when the acetic acid derivative is poor inreactivity, an ester derivative thereof or a cyano derivative thereof isfirst prepared and, then, hydrolyzed to obtain the above-describedcompound or derivative.A1—CH₂COOH  Formula (5)A1—CH₂COOH  Formula (6)A2—CO—C(A1)═C(A2)—X  Formula (7-1)A2—CO—C(A1)═C(A2)—C (A1)═C(A2)—X  Formula (7-2)

wherein A1, A2 and X each represent a same compound as that describedabove.

Specific examples of compounds (dyes) used in the present invention willnow be shown below.

Compound examples of derivatives (compounds represented by theabove-described formula (2)) in a case of n=1 in the formula (1) areshown in Table 1. Compound Nos. 1 to 27 in Table 1 show examples ofcompounds represented by the formula (8) mentioned below, whereascompound Nos. 28 to 32 show examples of compounds in which X in theabove-described formula (2) is a 4-(N-ethyl carbazole) group, a group offerrocene, a group of 2-thiophene, a group of ruthenocene and a group ofphthalocyanine, respectively. 4-DMA in Table 1 means 4-dimethyl aniline.Further, examples of R1, R2, B1, B2, B3 and B4 in the formula (8) areshown in Table 1.

TABLE 1 (8)

Compound B1 B2 R1 R2 B3 B4 1 CN H CH3 CH3 H H 2 CN H C2H5 C2H5 H H 3 CNH C4H9 C4H9 H H 4 CN H C8H17 C2H5 H H 5 CN H C18H37 C18H37 H H 6 CN HC2H4OCH3 C2H4OCH3 H H 7 CN H Phenyl Phenyl H H 8 CN H p-tolyl p-tolyl HH 9 CN H 4-DMA 4-DMA H H 10 CN H C2H4Cl CH3 H H 11 CN H Phenyl Phenyl HH 12 CN H CH3 CH3 H CH3 13 CN H CH3 CH3 H Cl 14 CN H H COCH3 H H 15 CN HC2H5 C2H5 OCH3 CH3 16 CN H C2H5 C2H5 OCH3 NHCOCH3 17 CN CN C2H5 C2H5 H H18 CN CN C2H4CN 2H4CN H H 19 COOH H C2H4Br C2H4Br H H 20 CONHC2H5 H H HH H 21 CN H H H H H 22 NO2 H CH3 C4H9 H H 23 COOCH3 H CH3 CH3 H H 24COCH3 H C2H5 C2H5 H H 25 CONH2 H C2H5 H H H 26 CN 4-DMA CH3 CH3 H H 27CN Cl CH3 CH3 H H 28 CN H X = 4-(N-ethylcarbazole) 29 CN H X = ferrocene30 CN H X = 2-thiophene 31 CN CN X = ruthenocene 32 CN H X =phtalocyanine

Examples of derivatives (compounds of the above-described (3)) of n=2 inthe formula (1) are shown in Table 2.

Compound Nos. 33 to 45 are compound examples represented by the formula(9) described below in a case in which X is a substituted anilino groupin the formula (3) whereas compound Nos. 46 to 49 are examples ofcompounds in a case in which X in the formula (3) is a 4-(N-ethylcarbazole) group, a group of 2-thiophene, a group of ferrocene or agroup of phthalocyanine, respectively. Specific examples of respectivegroup of substituents, R1, R2 and C1 to C6, are shown in Table 2.Further, in Table 2,4-dimethyl aniline and 4-diethyl aniline areabbreviated as 4-DMA and 4-DEA, respectively.

TABLE 2 (9)

Compound C1 C2 C3 C4 R1 R2 C5 C6 33 CN H H H CH3 CH3 H H 34 COOH H H HCH3 CH3 H H 35 CN H H H C2H4COOH C2H4COOH H H 36 CN H H Cl C2H5 C2H5 H H37 COOH H H H C2H5 C2H5 OCH3 NHCOCH3 38 CN H H H C2H5 C2H5 H OH 39 NO2 HH H CH3 CH3 H H 40 COOH H H H phenyl phenyl H 41 CN H H H phenyl phenylH 42 COOH H H H 4-DEA 4-DEA H H 43 COOH H H 4-DMA CH3 CH3 H H 44 COOC2H5H H H C2H5 C2H5 H H 45 COOPH H H H C8H17 CH3 H H 46 CN H H H X =4-(N-ethlycarbazole) 47 COOH H H H X = 2-thiophene 48 CN H H H X =ferrocene 49 CN H H H X =phtalocyanine

Other examples of compounds which are derivatives of n=1 and 2 in theformula (1) are shown below.

Representative examples of compounds which are derivatives of n=3 ormore are shown below.

A dye-sensitized photoelectric conversion device according to thepresent invention is, for example, a device in which a thin film of anoxide semiconductor is produced on a substrate by using oxidesemiconductor fine particles and then a dye is allowed to be adsorbed onthe thus-produced thin film. As fine particles of the oxidesemiconductor, a metal oxide is preferable; specific examples of suchmetal oxides include oxides of titanium, tin, zinc, tungsten, zirconium,gallium, indium, yttrium, niobium, tantalum, vanadium and the like.Among these oxides, oxides of titanium, tin, zinc, niobium, tungsten andthe like are preferable and, above all, titanium oxide is mostpreferable. These oxide semiconductors can be used either alone ormixture thereof. An average particle diameter of the fine particles ofthe oxide semiconductor is ordinarily from 1 nm to 500 nm and preferablyfrom 5 nm to 100 nm. These fine particles of the oxide semiconductor canalso be used in a state of mixtures of large particle diameter ones andsmall particle diameter ones.

An oxide semiconductor thin film can be produced by a method in whichoxide semiconductor fine particles are directly vapor-deposited on asubstrate to form a thin film, a method in which an oxide semiconductorthin film is electrically precipitated by using a substrate as anelectrode or a method in which a slurry of semiconductor fine particlesto be described below is applied on a substrate, dried and cured orsintered. From the standpoint of performance of an oxide semiconductorelectrode, a method which uses the slurry is preferable. In this method,the slurry can be obtained by dispersing the oxide semiconductor fineparticles which, are in a secondary agglomeration state by a normalmethod such that an average primary particle diameter thereof comes tobe from 1 nm to 200 nm in a dispersion medium.

Any dispersion medium of the slurry is usable, so long as it is capableof dispersing the semiconductor fine particles. Water or an organicsolvent such as an alcohol such as ethanol or the like, a ketone such asacetone, acetylacetone or the like or a hydrocarbon such as hexane orthe like is used and may be used in mixture thereof and, further, it isfavorable to use water from a standpoint that it suppresses viscositychanges.

A temperature of sintering a substrate which has been coated with theslurry is ordinarily 300° C. or more, preferably 400° C. or more and amaximum allowable temperature thereof is approximately not greater thana melting point (softening point) of the substrate, ordinarily 900° C.as an upper limit and preferably600° C. or less. Further, a period oftime of sintering the substrate is not particularly limited, but ispreferably within about 4 hours. Thickness of the thin film on thesubstrate is ordinarily from 1 μm to 200 μm and preferably from 5 μm to50 μm.

The oxide semiconductor thin film may be subjected to a secondarytreatment. Namely, for example, the thin film can directly be immersedtogether with the substrate in a solution of an alkoxide, a chloride, anitride, a sulfide or the like of the same metal as the semiconductorand, then, dried or sintered again to enhance performance of thesemiconductor thin film. Examples of such metal alkoxides includetitanium ethoxide, titanium isopropoxide, titanium t-butoxide,n-dibutyl-diacetyl tin and the like and an alcoholic solution thereof isused. Examples of such chlorides include titanium tetrachloride, tintetrachloride, zinc chloride and the like and an aqueous solutionthereof is used.

Next, a method to adsorb a dye on the oxide semiconductor thin film isexplained. As the above-described method for adsorbing the dye thereon,mentioned is a method in which a substrate on which the above-describedoxide semiconductor thin film has been provided is immersed in asolution obtained by dissolving a dye in a solvent capable of dissolvingthe dye or in a dispersion liquid obtained by dispersing a dye which hasa low solubility. A concentration of the dye in the solution or thedispersion liquid is appropriately determined depending on dyes. Thesemiconductor thin film formed on the substrate is immersed in thesolution. An immersion temperature is approximately from normaltemperature up to a boiling point of the solvent and, further, animmersion period of time is from about 1 hour to about 48 hours.Specific examples of solvents to be used in dissolving the dye includemethanol, ethanol, acetonitrile, dimethylsulfoxide, dimethylformamideand the like. A concentration of the dye in the solution is ordinarilyfavorably from 1×10⁻⁶ M to 1 M and preferably from 1×10⁻⁶ M to 1×10⁻¹ M.In such a way as described above, a photoelectric conversion device ofthe oxide semiconductor thin film sensitized with the dye can beobtained.

The dye to be adsorbed may be composed of one type or a mixture of twoor more types. When the dyes are mixed, the dyes which have an acrylicacid part according to the present invention may be mixed there among ormixed with any one of other dyes and metal complex dyes. Particularly,by mixing dyes having different absorption wavelengths from one another,a wider absorption wavelength can be utilized and, as a result, a solarcell having high conversion efficiency can be obtained. By utilizingthree or more types of dyes, it becomes possible to even fabricate anoptimum solar cell.

As examples of such metal complex dyes to be utilized for the mixture,there is no particular limitation thereon, but a ruthenium complex whichhave been disclosed in J. Am. Chem. Soc., 115, 6382 (1993) orJP-A-2000-26487, phthalocyanine, porphyrin and the like are preferable.Examples of organic dyes to be utilized for the mixture include dyessuch as metal-free phthalocyanine, metal-free porphyrin, or methine-typedyes such as cyanine, merocyanine, oxonol, a triphenyl methane type andthe like, a xanthene type, an azo type, an anthraquinone type and thelike. Among these dyes, the ruthenium complex and methine-type dyes suchas merocyanine and the like are preferable. A ratio of the dyes to bemixed is not particularly limited and is optimized according torespective dyes. However, it is ordinarily preferable to mix them in therange of between each equivalent mol and about 10% mol or more for adye. When mixed dyes are adsorbed on the thin film of the oxidesemiconductor fine particles by using a solution in which such mixeddyes are mix-dissolved or dispersed, a concentration of entire dyes inthe solution may be same as that in a case in which only one type of dyeis adsorbed.

When the dye is adsorbed on the thin film of the oxide semiconductorfine particles, it is effective to adsorb the dye in the presence of aninclusion compound in order to prevent dyes from associating with eachother. Examples of such inclusion compounds include steroid-typecompounds such as cholic acid and the like, crown ethers, cyclodextrin,calixarene, polyethylene oxide and the like. Cholic acid, polyethyleneoxide and the like are preferable. Further, after the dye is adsorbedthereon, a surface of a semiconductor electrode may be treated with anamine compound such as 4-t-butylpyridine or the like. As a method forsuch treatment, for example, a method in which a substrate having a thinfilm, on which the dye is adsorbed, of the semiconductor fine particlesis immersed in an ethanol solution of an amine or the like can beadopted.

The solar cell according to the present invention comprises aphotoelectric conversion device electrode in which the dye is adsorbedon the above-described oxide semiconductor thin film, a counterelectrode and a redox electrolyte or a hole transfer material. The redoxelectrolyte may be a solution in which a redox pair is dissolved in asolvent, a gel electrolyte that a polymer matrix is impreganated with aredox pair or a solid electrolyte such as a fused salt. Examples of holetransfer materials include an amine derivative, an electricallyconductive polymer such as polyacetylene, polyaniline, polythiophene orthe like, a material using a discotic liquid crystal phase such aspolyphenylene and the like. The counter electrode to be used ispreferably an electrode which has electric conductivity andcatalytically acts on a reduction reaction of the redox electrolyte. Forexample, a material in which platinum, carbon, rhodium, ruthenium or thelike is vapor-deposited on glass or a polymer film, or electricallyconductive fine particles are applied thereon can be used.

Examples of redox electrolytes to be used in solar cells according tothe present invention include a halogen redox electrolyte comprising ahalogen compound and halogen molecule having a halogen ion as a counterion, a metal oxidation-reduction type electrolyte of a metal complex orthe like such as ferrocyanate-ferricyanate, ferrocene-ferricinium ion orthe like and an aromatic redox electrolyte such asalkylthiol-alkyldisulfide, a viologen dye, hydroquinone-quinone or thelike, and the halogen redox electrolyte is preferable. As the halogenmolecule in the halogen redox electrolyte comprising halogencompound-halogen molecule, mentioned is, for example, an iodinemolecule, a bromine molecule or the like, and the iodine molecule ispreferable. Further, examples of the halogen compounds having a halogenion as a counter ion include a halogenated metal salt, for example, LiI,NaI, KI, CsI, CaI₂ or the like, or an organic quaternary ammonium saltof halogen such as tetraalkylammonium iodide, imidazolium iodide,pyridinium iodide or the like, and a salt-type compound having theiodine ion as a counter ion is preferable. Examples of such salt-typecompounds having the iodine ion as a counter ion include lithium iodide,sodium iodide, a trimethyl iodide ammonium salt and the like.

Further, when the redox electrolyte is constituted in a solution statecontaining itself, an electrochemically inert solvent is used as asolvent. Examples of such solvents include acetonitrile, propylenecarbonate, ethylene carbonate, 3-methoxypropionitrile,methoxyacetonitrile, ethylene glycol, propylene glycol, diethyleneglycol, triethylene glycol, γ-butyrolactone, dimethoxyethane, diethylcarbonate, diethyl ether, diethyl carbonate, dimethyl carbonate,1,2-dimethoxy ethane, dimethyl formamide, dimethyl sulfoxide,1,3-dioxolane, methyl formate, 2-methyl tetrahydrofuran,3-methoxy-oxaziridine-2-one, sulfolane, tetrahydrofuran, water and thelike. Among these solvents, particularly, acetonitrile, propylenecarbonate, ethylene carbonate, 3-methoxypropionitrile,methoxyacetonitrile, ethylene glycol, 3-methoxyoxaziridine-2-one and thelike are preferable. These solvents may be used either alone or in anycombination of two or more types. In a case of the gel electrolyte,mentioned is a gel electrolyte which uses a polyacrylate orpolymethacrylate resin or the like as a matrix. A concentration of theredox electrolyte is ordinarily from 0.01% by weight to 99% by weightand preferably from about 0.1% by weight to about 90% by weight.

The solar cell according to the present invention can be obtained byarranging the counter electrode against an electrode of thephotoelectric conversion device adsorbing the dye in the oxidesemiconductor thin film on the substrate such that the electrode of thephotoelectric conversion device is interposed, and filling a solutioncontaining the redox electrolyte between the electrode of thephotoelectric conversion device and the counter electrode.

EXAMPLES

The present invention is now more specifically described with referenceto Examples. However, it should be noted that these Examples should notbe interpreted as limiting the present invention. Unless statedotherwise, all parts and percentages in these Examples are given bymass.

Synthesis Example 1

One part of cyanoacetic acid and 2 parts of N,N-diethylaminobenzaldehyde were dissolved in 10 parts of ethanol and then 0.6 part ofpiperazine anhydride was added thereto dropwise. The resultant mixturewas reacted under reflux for 2 hours and then cooled to obtain a solid.The thus-obtained solid was filtered, washed and dried, and thenrecrystallized with a mixed solvent of ethanol and hexane(ethanol:hexane=3:1), filtered, washed and thereafter dried to obtain2.1 parts of a compound (2).

Melting point: from 185° C. to 187° C. (mel-temp used)

1H-NMR(δ(ppm): d6-DMSO)): 1.12(t, CH3, 6H), 3.43(q, CH2, 4H), 6.77(d,arom, 2H), 7.83(d, arom, 2H), 7.89(s, ═CH—, 1H)

Mass spectrometry: M−1=243 (mw=244) (measured by using TOF MS availablefrom Micromass Ltd. Under ESI negative mode)

Absorption maximum (methanol): 406 mm

Luminescence maximum (methanol): 476 mm

Synthesis Example 2

0.8 part of malonic acid and 1 part of 4-dimehylamino cinnamic aldehydewere dissolved in 10 parts of ethanol and, then, 0.3 part of piperazineanhydride was added thereto dropwise. The resultant mixture was reactedunder reflux for 2 hours and then cooled to obtain a solid. Thethus-obtained solid was filtered, washed and dried, and thenrecrystallized with a mixed solvent of ethanol and hexane, filtered,washed and thereafter dried to obtain 1.0 parts of a compound (34).

Melting point: from 160° C. to 165° C. (mel-temp used)

1H-NMR(δ(ppm): d6-DMSO)): 3.02(s, CH3, 6H), 6.74(d, arom, 2H), 7.00(d,═CH—, 1H), 7.40(d,arom, 2H), 7.65(d, ═CH—, 1H), 8.11(dd, ═CH—, 1H)

Mass spectrometry: M−1=260 (mw=261) (measured by using TOF MS ESIavailable from Micromass Ltd. under negative mode)

Absorption maximum (methanol): 429 mm

Luminescence maximum (methanol): 562 mm

Compounds described below were synthesized by using materialscorresponding to respective target compounds in a same manner as in theabove-described synthesis examples. Compound numbers and respectivephysical properties are shown in Table 3.

TABLE 3 Syn- thesis Melting Absorption Luminescence Mass spectrometryexample point maximum maximum (molecular weight) 1 212–214 416 nm 469 nmM − 1 = 215(216) 7 230–235 418 nm 540 nm M − 1 = 339(340) 28 165–166 381nm 489 nm M − 1 = 289(290) 29 155–160 317 nm — M − 1 = 280(281) 33165–170 433 nm 565 nm M − 1 = 241(242)Example

In regard to Examples from 1 to 21, a dye having an acrylic acid partwas dissolved in EtOH in a concentration of 3×10⁻⁴ M. In regard toExamples from 22 to 25, dyes were dissolved in EtOH such that each dyecame to be in a concentration of 1.5×10⁻⁴ M. In regard to Example 26,dyes were dissolved in EtOH such that each dye came to be in aconcentration of 1×10⁻⁴ M. In regard to Example 27, dyes were dissolvedin EtOH such that each dye came to be in a concentration of 7.5×10⁻³ M.In each of the resultant solutions, a porous substrate (semiconductorthin film electrode prepared by the steps of: dispersing titaniumdioxide P-25 available from Nippon Aerosil Co., Ltd. in an aqueoussolution of nitric acid, applying the thus-dispersed titanium dioxide ona transparent electrically conductive glass electrode in a thickness of50 μm; and sintering the resultant electrode at 450° for 30 minutes) wasimmersed at room temperature for from 3 hours to one night to adsorbedthe dye therein, washed with a solvent and dried to obtain aphotoelectric conversion device of a dye-sensitized semiconductor thinfilm. Further, in Examples 2, 7, 9, 13, 16, 17, 18, 22, 26 and 27, anaqueous solution of 0.2 M titanium tetrachloride was added dropwise to atitanium oxide thin film portion of the semiconductor thin filmelectrode, it was left to stand at room temperature for 24 hours, andthen washed with water and sintered again at 450° for 30 minutes toobtain a titanium tetrachloride-treated semiconductor thin filmelectrode. The dye was adsorbed in the thus-obtained titaniumtetrachloride-treated semiconductor thin film electrode in the samemanner.

Further, in Examples 4 and 10, when the dye solution was prepared,cholic acid was added as an inclusion compound such that it became to be3×10⁻⁵ M at the time the dye was adsorbed and, then, the resultant dyesolution was adsorbed in the semiconductor thin film to obtain a cholicacid-treated dye-sensitized semiconductor thin film. An electricallyconductive glass whose surface had been sputtered by platinum was fixedsuch that the thus-obtained dye-sensitized semiconductor thin film isinterposed and, then, a gap generated therebetween was filled with anelectrolyte-containing solution. Three types of suchelectrolyte-containing solutions were prepared. Anelectrolyte-containing solution A was prepared by dissolving iodine,lithium iodide, 1,2-dimethyl-3-n-propyl imidazolium iodide, t-butylpyridine in 3-methoxypropionitrile such that concentrations thereof in3-methoxypropionitrile became 0.1 M, 0.1 M, 0.6 M and 1 M, respectively.An electrolyte-containing solution B was prepared by dissolving iodineand tetra-n-propyl ammonium iodide in a mixed solution of ethylenecarbonate and acetonitrile in a mixing ratio of 6 to 4 such thatconcentrations thereof in the mixed solution became 0.02 M and 0.5 M,respectively. An electrolyte-containing solution C was prepared bydissolving iodine and lithium iodide in propylene carbonate such thatconcentrations thereof became 0.05 M and 0.55 M in propylene carbonate,respectively.

A size of a cell used for measurements was set such that an executionpart thereof was 0.25 cm². A light source was set to be 100 mW/cmthrough an AM 1.5 filter using a 500 W xenon lamp. Short circuitcurrent, open circuit voltage, conversion efficiency and a form factorwere measured by using a potentiogalvanostat.

Further, measurements on Comparative Examples were conducted in a samemanner as in Example 1 by using the following Ru complex dye (131) and amerocyanine dye:

TABLE 4 (131)

(132)

Short Open TiCl4 Cholic Compound circuit circuit Conversion treatment ofacid Electrolytic No. current voltage efficiency thin film treatmentsolution Example  1 1 5.7 0.56 1.5 Untreated Untreated B  2 2 5.1 0.742.2 Treated Untreated B  3 7 5.4 0.63 2.1 Untreated Untreated A  4 7 4.70.67 1.8 Untreated Treated B  5 10 4.6 0.65 2.0 Untreated Untreated B  612 5.5 0.67 2.3 Untreated Untreated B  7 13 5.0 0.74 2.3 TreatedUntreated B  8 28 4.5 0.65 1.8 Untreated Untreated B  9 28 4.3 0.74 2.0Treated Untreated B 10 29 0.4 0.46 0.1 Untreated Treated A 11 33 7.10.62 2.3 Untreated Untreated C 12 34 7.3 0.59 2.1 Untreated Untreated C13 40 6.9 0.58 2.5 Treated Untreated B 14 41 5.7 0.57 2.1 UntreatedUntreated B 15 50 5.0 0.53 1.7 Untreated Untreated B 16 86 2.3 0.66 1.0Treated Untreated B 17 88 2.8 0.50 0.9 Treated Untreated B 18 90 3.20.67 1.4 Treated Untreated B 19 106 6.3 0.56 2.0 Untreated Untreated B20 107 4.9 0.58 1.9 Untreated Untreated A 21 10 4.6 0.65 2.0 UntreatedUntreated B 22 2 + 131 12.3 0.70 5.4 Treated Untreated B 23 2 + 41 9.60.61 2.4 Untreated Untreated B 24 33 + 41 9.3 0.55 2.6 UntreatedUntreated B 25 40 + 132 9.2 0.64 3.8 Untreated Untreated B 26 7 + 41 +10.5 0.66 4.1 Treated Untreated B 132 27 2 + 7 + 10.1 0.67 4.2 TreatedUntreated B 41 + 132 Comparative Example  1 131 11.0 0.71 4.5 UntreatedUntreated B  2 132 6.3 0.56 2.4 Untreated Untreated B

INDUSTRIAL APPLICABILITY

In a dye-sensitized photoelectric conversion device according to thepresent invention, a solar cell having high conversion efficiency wasable to be provided by using a dye having an acrylic acid part.

1. A photoelectric conversion device, comprising oxide semiconductorfine particles sensitized with at least one dye represented by thefollowing formula (1) having an acrylic acid part:HOOC—(A1)C═C(A2)−{(A1)C═C(A2)}_(n−1)−X  (1) wherein A1 and A2 eachindependently represent a carboxyl group, a cyano group, analkoxycarbonyl group, an acyl group, a nitro group, a cyclic hydrocarbonresidue which may be substituted, a heterocyclic residue which may besubstituted, an amino group which may be substituted, a hydroxyl group,a hydrogen atom, a halogen atom or an alkyl group which may besubstituted; X represents an aromatic hydrocarbon residue which may besubstituted, a heterocyclic residue which may be substituted, or anorganic metal complex residue which may be substituted; n represents aninteger of from 1 to 6; when n is 2 to 6 and a plurality of A1 and aplurality of A2 are present, each A1 and each A2 independently representany one of the groups or residues defined above for A1 and A2 which maybe the same with or different from each other, and further, except forthe A1 bond to the carbon atom to which the carboxyl group in an acrylicpart is bound, two A1s or each A1 in a plurality of A1, two A2s or eachA2 in a plurality of A2 and X may be bound together to form a ringselected from the group consisting of a benzene ring, a naphthalenering, an indene ring, a pyridine ring, a pyrazine ring, a thiophenering, a furan ring, an oxazole ring, a thiazole ring, an indole ring, abenzothiazole ring, a benzoxazole ring, a quinoline ring and a carbazolering.
 2. The photoelectric conversion device as set forth in claim 1,wherein n is from 1 to 3 in the formula (1).
 3. The photoelectricconversion device as set forth in claim 1, characterized in that atleast one of A1 and A2 or, when a plurality of A1 and a plurality of A2are present, at least one thereof is a cyano group or a carboxyl groupin the formula (1).
 4. The photoelectric conversion device as set forthin claim 3, characterized by that A1 in the formula (1) is a cyano groupor a carboxyl group and wherein the A1 binds to the same carbon atom asthe carboxyl group in an acrylic part.
 5. The photoelectric conversiondevice as set forth in any one of claims 1 to 4, wherein X in theformula (1) is an aromatic hydrocarbon residue having a substitutedamino group.
 6. The photoelectric conversion device as set forth inclaim 3, wherein X of the formula (1) is an aromatic hydrocarbon residuehaving a substituted amino group and comprising an aromatic ring havingfrom 6 to 16 carbon atoms.
 7. The photoelectric conversion device as setforth in claim 6, wherein X of the formula (1) is a phenyl group havinga mono- or di- (C1 to C4) alkyl-substituted amino group, wherein saidphenyl group may further be substituted by one or two substituentsselected from the group consisting of a halogen atom, an alkyl grouphaving from 1 to 4 carbon atoms and an alkoxy group having from 1 to 4carbon atoms.
 8. The photoelectric conversion device as set forth inclaim 3, wherein X is an aromatic hydrocarbon residue having asubstituted amino group or A2 or X is a heterocyclic residue which is a5- or 6-membered ring containing from 1 to 3 hetero atoms and may besubstituted, or a heterocyclic residue comprising a condensed ring,having from 8 to 15 carbon atoms, which contains a 5- or 6-memberedheterocycle containing from 1 to 3 hetero atoms, or the ring formed bybinding of two A1s or each A1 in a plurality of A1, two A2s or each A2in a plurality of A2 and X is a pyridine ring, a pyrazine ring, athiophene ring, a furan ring, an oxazole ring, a thiazole ring, anindole ring, a benzothiazole ring, a benzoxazole ring, a quinoline ring,or carbazole ring, characterized by comprising oxide semiconductor fineparticles comprising at least one dye having an acrylic acid part andsensitized with simultaneously using two or more sensitizing dyes. 9.The photoelectric conversion device as set forth in claim 7,characterized by comprising oxide semiconductor fine particlessensitized by simultaneously using three or more sensitizing dyes. 10.The photoelectric conversion device as set forth in any one of claims 1to 4, wherein the oxide semiconductor fine particles comprise titaniumdioxide as an essential component.
 11. The photoelectric conversiondevice as set forth in any one of claims 1 to 4, wherein a dye isabsorbed in the oxide semiconductor fine particles in the presence of aninclusion compound.
 12. A solar cell, characterized by comprising thephotoelectric conversion device as set forth in any one of claims 1 to4.
 13. The photoelectric conversion device as set forth in claim 7,characterized by comprising oxide semiconductor fine particlescomprising at least one dye having an acrylic acid part and sensitizedwith simultaneously using two or more sensitizing dyes.
 14. Thephotoelectric conversion device as set forth in claim 13, wherein theoxide semiconductor fine particles comprise titanium dioxide as anessential component.
 15. The photoelectric conversion device as setforth in claim 7, wherein a dye is absorbed in the oxide semiconductorfine particles in the presence of an inclusion compound.
 16. Thephotoelectric conversion device as set forth in claim 13, wherein a dyeis absorbed in the oxide semiconductor fine particles in the presence ofan inclusion compound.
 17. The photoelectric conversion device as setforth in claim 1, wherein, when n is 1, X of the formula (1) is a phenylgroup having a mono- or di- (C₁ to C₂₀) alkyl-substituted amino group orhaving a mono-or di-phenyl amino group wherein the phenyl may besubstituted by methyl, or X is carbazole which may be substituted, andwhen n is 2 or 3, X of the formula (1) is an aromatic hydrocarbonresidue which may be substituted, a heterocyclic residue which may besubstituted, or an organic metal complex residue which may besubstituted.